1. Field
One or more embodiments of the present disclosure relate to a method and apparatus of generating a sound field effect.
2. Description of the Related Art
A three-dimensional (3D) virtual stereoscopic technology based on a two-channel system is a technology that gives a sense of direction and realism to a two-channel sound source, thereby providing an audience with an atmosphere of a virtual hearing space. That is, the technology is a stereoscopic surround localization technology that places virtual sound sources around the audience to enable the audience to experience being surrounded by sound.
As an example, a stereoscopic surround localization system may receive two-channel stereo sound as a sound source, may expand the sound to a plurality of channels (as an example, 5.1) by performing sound image localization of the sound to a location of a rear left channel, a rear right channel, a center channel, and a subwoofer speaker, and may output the sound via a front left speaker and a front right speaker by mixing the sound using the two-channel sound. Also, a headphone-based virtual surround system may perform filtering of a frequency using a head related transfer function (HRTF) filter, may control volume, may generate a phase difference to follow a method that an actual sound arrives to human ears, and may associate with an image signal such as a portable phone, to provide a virtual 3D effect.
Also, a sound in-head localization phenomenon that readily occurs by headphones or an earphone acts as a hindrance to establish the virtual 3D effect. In this instance, the in-head localization phenomenon is a phenomenon in which the audience only experiences a sense of direction without a sense of distance. Accordingly, a sound image externalization technology that generates a virtual sound image outside a head using a reflection sound and a reverberation effect is required.